Cardiac diastolic dysfunction in renal-transplant recipients is associated with increased circulating Adrenomedullin

Renal transplantation is an excellent therapeutic alternative for end-stage renal diseases. Nevertheless, the cardiac function is often impaired in renal-transplant patients (RTR) and importantly determines their prognosis. Adrenomedullin (ADM), a peptide involved in cardiovascular homeostasis, is believed to protect both cardiac and renal functions - by increasing local blood flows, attenuating the progression of vascular damage and remodelling and by reducing glomerular injury - and might be involved in renal-transplantation physiopathology. This work was performed to investigate whether an increase in circulating ADM might be related to RTR cardiac function.

Twenty-nine subjects, 19 RTR and 10 healthy subjects, participated in the study. After 15 min rest in supine position, heart rate and systemic blood pressure were measured together with cyclosporine through levels, creatinine and ADM. Systolic and diastolic cardiac functions were assessed, using Doppler echocardiography.

Subjects were similar concerning age, weight, heart rate and blood pressure. Creatinine and ADM (53.8 +/- 6.9 vs. 27.2 +/- 4.1 pmol/L, p = 0.02) were significantly increased in RTR (73 +/- 10 months after transplantation). Cardiac systolic function was normal, but a reduced mitral E:A ratio was observed in RTR (0.90 +/- 0.06 vs. 1.38 +/- 0.10, p < 0.001), reflecting their impaired left ventricular relaxation. Such a ratio was negatively correlated with ADM (r = -0.55, p = 0.002).

RTR present with an increased ADM is likely related to cardiac diastolic dysfunction. In view of its protective effect on the cardiovascular system, these data support further studies to better define the role and the therapeutic potential of ADM after renal transplantation.